# What is the Greatest Common Factor (GCF) of 4 and 12?

Jan 7, 2018

$4$

#### Explanation:

$4 = 2 \times 2$

$12 = 2 \times 2 \times 3$

The greater common factor $= 2 \times 2 = 4$

Jan 8, 2018

$G C F \left(4 , 12\right) = 4$

#### Explanation:

another approach is to list the factors out and pick out the common ones

Factors of $4 : \left\{\textcolor{red}{1 , 2 , 4}\right\}$

factors of$12 : \left\{\textcolor{red}{1 , 2 ,} 3 , \textcolor{red}{4} , 6 , 12\right\}$

common factors$: \left\{1 , 2 , 4\right\}$

$G C F \left(4 , 12\right) = 4$